To take the advantage
of the synergy of atom filling and pressure regulation, atom Pb was
assumed to play the role of fillers to occupy the Sb-icosahedron voids.
In this paper, skutterudite Pb
x
Co4Sb11.5Te0.5 materials have been synthesized
by high-pressure and high-temperature (HPHT) method with 0.5 h processing
time. Although the increase of Pb filling rate increased the electrical
resistivity of samples, it reduced the thermal conductivity of samples
significantly. When the synthesis pressure increased, the Seebeck
coefficients of Pb0.2Co4Sb11.5Te0.5 increased, and the thermal conductivity decreased. The
crystal morphology and structure of samples, which can effectively
affect the thermoelectric properties of materials, were investigated
with XRD, Raman spectra, SEM mapping, and HR-TEM analysis.